The World Health Organisation (WHO) said it was moving to update its guidelines on treating people stricken with Covid-19 to reflect results of a clinical trial that showed a cheap, common steroid can help save critically ill patients.

Trial results announced on Tuesday showed dexamethasone, used since the 1960s to reduce inflammation in diseases such as arthritis, cut death rates by around a third among the most severely ill Covid-19 patients admitted to hospital.

The WHO’s clinical guidance for treating patients infected with the new coronavirus is aimed at doctors and other medical professionals and seeks to use the latest data to inform clinicians on how best to tackle all phases of the disease, from screening to discharge.

“This is the first treatment to be shown to reduce mortality in patients with Covid-19 requiring oxygen or ventilator support,” WHO Director-General Tedros Adhanom Ghebreyesus said in a statement, according to Reuters.